Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/04—Processes of manufacture in general
  • H01M4/0402—Methods of deposition of the material
  • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
  • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/134—Electrodes based on metals, Si or alloys
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/139—Processes of manufacture
  • H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
  • H01M4/381—Alkaline or alkaline earth metals elements
  • H01M4/382—Lithium
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
  • H01M4/621—Binders
  • H01M4/622—Binders being polymers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
  • H01M4/624—Electric conductive fillers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/66—Selection of materials
  • H01M4/661—Metal or alloys, e.g. alloy coatings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/66—Selection of materials
  • H01M4/665—Composites
  • H01M4/667—Composites in the form of layers, e.g. coatings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/66—Selection of materials
  • H01M4/668—Composites of electroconductive material and synthetic resins
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/70—Carriers or collectors characterised by shape or form
  • H01M4/72—Grids
  • H01M4/74—Meshes or woven material; Expanded metal
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/70—Carriers or collectors characterised by shape or form
  • H01M4/72—Grids
  • H01M4/74—Meshes or woven material; Expanded metal
  • H01M4/742—Meshes or woven material; Expanded metal perforated material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M2004/021—Physical characteristics, e.g. porosity, surface area
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
  • H01M2004/027—Negative electrodes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present disclosure generally relates to the field of electrochemical devices.
• the present disclosure is directed to anodes comprising an electrically conductive layer between an anode-active material and a current collector, and electrochemical devices incorporating such anodes.
• Rechargeable, or secondary, lithium-metal batteries offer volumetric and gravimetric energy densities higher than current lithium-ion batteries.
• lithium-ion batteries which contain anodes (negative electrode) formed from an intercalant material such as graphite
• lithium foil anode-active material
• Li/Cu/Li lithium-copper-lithium
• lithium is soft and sticky, and it is difficult by conventional roll-milling processes to produce ultra-thin ( ⁇ 50 um thick) lithium foil having width more than 120 mm. That width constraint consequently limits the size of the anode and cells that can be built using lamination techniques.
• FIGS. 1 A and IB illustrate a conventional approach to producing conventional Li/Cu/Li anodes (represented by dashed line regions 10) using a roll-to-roll process 12 involving continuous lamination of ultra-thin lithium-foil ribbons 14A and 14B on both sides of a copper-foil web 16 to form a webbed anode precursor 18.
• the width, Ww, of the copper-foil web 16 is usually wider than the width, Wf, of the lithium foil, and the laminated structure typically has a bare copper region 16A along at least one edge of the copper-foil web.
• the bare copper region 16A is provided for forming electrical tabs 10A for enabling electrical contact to the Li/Cu/Li anodes 10 that are stamped out from the webbed anode precursor 18 when the Li/Cu/Li anodes are assembled into a stacked “jellyroll” of an electrochemical cell. Without the electrical tabs 10A, it would be difficult to connect multiple layers of the Li/Cu/Li anodes 10 in the stacked jellyroll to an external electrical lead (not shown) in the finished electrochemical cell.
• the width Wf of the lithium-foil web 16 is limited to about 120 mm when using the desired ultra-thin lithium foil, and this limits the size of the Li/Cu/Li anodes, such as the Li/Cu/Li anodes 10 of FIGS. 1A and IB, that can be made using conventional roll-to-roll lamination techniques, which correspondingly severely limits the size of lithium-metal electrochemical cells (not shown), for example, secondary lithium-metal-battery cells, that can be made with ultra-thin- lithium-metal anodes.
• this limitation hampers development of lithium-metal secondary cells for applications that require high-capacity batteries for practicable operation, such as electric vehicles, among others.
• the present disclosure is directed to an anode for an electrochemical device.
• the anode includes a current collector having a thickness and an active region, wherein the active region has first and second sides on opposite sides of the thickness; a first anode-active metal layer secured to the current collector on the first side of the active region; and a first electrically conductive layer between the current collector and the first anode-active metal layer, wherein the first electrically conductive layer secures the first anode-active metal layer to the current collector, wherein the first electrically conductive layer comprises poly(acrylic acid).
• the present disclosure is directed to an anode for an electrochemical device.
• the anode includes a current collector having a thickness and an active region, wherein the active region has first and second sides on opposite sides of the thickness; a first anode-active metal layer secured to the current collector on the first side of the active region; and a first electrically conductive layer between the current collector and the first anode-active metal layer, wherein the first electrically conductive layer secures the first anode-active metal layer to the current collector, the first electrically conductive layer comprising electrically conductive material and a binder binding the electrically conductive material in the first electrically conductive layer, wherein the electrically conductive material is present in the first electrically conductive layer in an amount in a range of about 50 wt.% to about 90 wt.%.
• FIG. 1A is a plan view of a portion of a conventional webbed anode precursor in a conventional roll- to-roll lamination process, illustrating Li/Cu/Li anodes prior to the Li/Cu/Li anodes being punched from the webbed anode precursor;
• FIG. IB is an enlarged exaggerated cross-sectional view of the conventional Li/Cu/Li webbed anode precursor as taken along line 1B-1B of FIG. 1 A before the anodes are punched from the webbed anode precursor;
• FIG. 2 is a flow diagram illustrating an example anode-forming lamination method of the present disclosure
• FIG. 3A is a partial plan view of an example webbed anode precursor and an example anode removed therefrom that can be made using the method of FIG. 2, with the webbed anode precursor shown in differing stages of processing, from application of an optional conductive-coating patch, to laminating of an anode-active-material patch, to removal of the anode from the webbed anode precursor;
• FIG. 3B is an enlarged exaggerated cross-sectional view of the example anode of FIG. 3 A as taken along line 3B-3B of FIG. 3 A;
• FIG. 4 is a high-level schematic view of an example roll-to-roll lamination process implementing the example anode-forming lamination method of FIG. 2;
• FIGS. 5 A through 5E are plan views of portions of differing webbed anode precursors illustrating examples of alternative arrangements of anode regions and anode-active-material patches (and conductive-coating patches, if used) on the webbed anode precursors;
• FIG. 6 is a graph of discharge capacity versus cycle life comparing cycle life performance of example Li/Cu/Li anodes made with and without a conductive-coating layer of the present disclosure.
• FIG. 7 is a high-level cross-sectional view of an electrochemical cell made using a plurality of anodes made in accordance with the present disclosure.
• the present disclosure is directed to methods of forming anodes for one or more electrochemical devices using certain lamination techniques.
• electrochemical devices that can benefit from an anode-forming lamination method of the present disclosure include metal-based secondary batteries and supercapacitors, among others.
• metal-based means that the electrochemical device at issue has one or more anodes that each comprise at least one metal layer that is the anode-active material.
• metals that can be used for the metal layer include, but are not limited to, lithium, sodium, potassium, magnesium, and aluminum, or an alloy containing such metal(s), among others.
• anodeforming lamination methods of the present disclosure allow metal anodes, especially alkali-metal anodes, such as lithium-metal anodes, to be made in sizes larger than conventionally laminated anodes made using the same anode-active metal. Such larger sizes translate, for example, into higher capacity secondary batteries that overcome limitations of conventional secondary batteries.
• lamination techniques disclosed herein can be cost effective, and cost of manufacturing is a particularly important parameter for manufacturing large- capacity secondary batteries needed for high-energy-demand applications, such as electric vehicles.
• the present disclosure is directed to anodes that include a current collector, a metal anode-active layer on one or both sides of the current collector, and an electrically conductive coating (or simply “conductive coating”) located between the current collector and each metal anode-active layer.
• the conductive coating is a conductive-carbonbased coating, which may include one or more forms of conductive carbon, a binder, and optionally particles of one or more metals.
• the conductive coating can include only particles of one or more metals and a binder.
• the conductive coating improves the securement of the alkali-metal layer to the current collector.
• a conductive coating of the present disclosure can prevent this delamination.
• a conductive coating of the present disclosure can also function to maintain contact with the lithium-metal layer when the lithium-metal layer is mostly converted to a porous mossy structure upon cycling.
• Using a conductive coating of the present disclosure can also assist in locating metal-foil sheets of anode active material on a current collector web and/or allow for new manufacturing techniques that leverage the excellent adhesive properties of some embodiments of the conductive coating.
• Metal-based anodes of the present disclosure that include a conductive coating can be made using any suitable method, such as any one of the anode-forming lamination methods disclosed herein or any suitable conventional methods.
• the present disclosure is directed to methods of making an electrochemical device using any of the methods disclosed herein and/or using any of the conductive-coating-containing anodes disclosed herein and electrochemical devices made using a method of the present disclosure and/or using any of the conductive-coating-containing anodes disclosed herein.
• the term “about”, when used with a corresponding numeric value, refers to ⁇ 20% of the numeric value, typically ⁇ 10% of the numeric value, often ⁇ 5% of the numeric value, and more often ⁇ 2% of the numeric value. In some embodiments, the term “about” can mean the numeric value itself.
• side when referring to an anode, layer, coating, foil, web, ribbon, or any other component, or region thereof, of an anode of the present disclosure or any other structure, or region thereof, used to form an anode of the present disclosure refers to the expanse of the component or structure that extends between edges of that component or structure in a direction perpendicular to the thickness of that component or structure.
• the “sides” of a component or structure are separated by the thickness of the component or structure.
• FIG. 2 illustrates an example anode-forming lamination method 200 of forming anodes 300 (only one shown detached) for one or more electrochemical device (not shown)
• FIGS. 3A and 3B illustrate a webbed anode precursor 304 and the anode 300 made using the method
• FIG. 4 illustrates an example roll-to-roll (R2R) processing system 400 for performing various steps of the anode-forming lamination method 200.
• R2R roll-to-roll
• the anode-forming lamination method 200 may be used to form a plurality of anodes 300 that may all be the same size as one another or may have differing sizes.
• Each anode 300 includes a current collector 308 having an active-material region 308 A and an electrically conductive tab, or just “tab”, 308B formed as an extension of the active-material region.
• the active- material region 308A contains an anode-active material 312 laminated to the anode 300 on one or both sides of the current collector 308, depending on the requirements for the anode design.
• the active-material region 308A has a length, La, in a direction parallel to the direction, Dt, of extension of the tab 308B from the active-material region, and the length La can be any suitable length, such as from about 50 mm to about 800 mm, from about 100 mm to about 600 mm, or about 100 mm or more, for example, when thickness, Tam of the active-material 312 is about 50 pm or less, in a range of about 15 pm to about 25 pm, or about 20 pm or less.
• the width, Wa, of the active-material region 308 A in a direction perpendicular to the length La can likewise be any suitable width, such as from about 10 mm to about 200 mm, from about 20 mm to about 150 mm, or less than about 120 mm when, for example, the thickness Tam is about 50 pm or less, in a range of about 15 pm to about 25 pm, or about 20 pm or less.
• the width Wa can be the maximum width of foil at a given thickness that can be formed from the chosen anode-active material using conventional foil-forming techniques, including widths greater than 200 mm.
• the current maximum width for lithium foil is about 120 mm of a thickness of about 50 pm or less, but future technologies may allow for greater widths, and techniques disclosed herein can easily keep pace with those technologies.
• Methods of the present disclosure enable production of lithium anodes, such as a lithium-based version of anode 300, with, for example, up to about 150 mm (Wa (FIG. 3 A)) x about 600 mm (La (FIG. 3A)) in areal dimensions or larger when the thickness Tam is about 50 pm or less, especially if industry devises ways of manufacturing lithium foils having widths greater than 120 mm that is effectively the current limit.
• a conventional lamination process yielded Li/Cu/Li anodes of about 53 mm x 45 mm in areal size at a lithium thickness of 20 pm, while a lamination method of the present disclosure, for example, lamination method 200 of FIG.
• anodes 300 having an active-area length La of 550 mm and an active-area width of 107 mm at the same lithium thickness (Tam).
• the cell capacity (Ah) and energy (Wh) will correspondingly be much higher (e.g., up to 25x higher, 50x higher, or more) for secondary batteries assembled with the anodes 300 made in accordance with the present disclosure, either with or without optional conductive-coating patches 328 (see below).
• Lithium-metal secondary batteries with a capacity more than 100 Ah that are required for high-energy-demand applications, such as electric vehicles, can be built using the disclosed methodologies.
• a 53 mm x 45 mm anode forms a ⁇ 4 Ah cell
• a 550 mm x 107 mm anode will form a ⁇ 100 Ah cell.
• the gravimetric and volumetric energy densities (Wh/Kg & Wh/L, respectively) of these batteries will also be higher.
• ⁇ 4 Ah versus -100 Ah cells there will be an increase in gravimetric energy density from about 400 Wh/kg to about 410 Wh/kg from the smaller cell to the larger cell.
• the anode 300 may include a conductive coating 316 between the anode-active material 312 and the current collector 308 on each side of the current collector where the anode-active material is present. It is usually desirable for the conductive coating 316, if present, and the anode-active material 312 to be about coextensive with the active-material region 308 A, i.e., have the about same length, Lee, and width, Wcc, as, respectively, the length La and the width Wa of the corresponding active-material region. As seen in FIG. 3 A, anode 300 is shown as being removed from webbed anode precursor 304 having been removed from a corresponding anode region 320(1) of the webbed anode precursor.
• FIG. 3A also shows two additional anode regions 320(2) and 320(3) on the webbed anode precursor 304 that will yield two additional anodes (not shown) once removed from the webbed anode precursor.
• Each anode region 320(1) to 320(3) includes an active-region portion 320A(l) to 320 A(3) and a tab portion 320B(l) to 320B(3).
• the anode region 320(2) includes the active anode material and is ready for the corresponding anode to be removed, while the anode region 320(3) does not yet include the active anode material.
• Example materials for each of the current collector 308, anode-active material 312, and conductive coating 316 are mentioned both above and below.
• the anode-forming lamination method 200 includes providing a currentcollector web 324.
• the current-collector web 324 may be provided as a ribbon 404 of current-collector material suitable for the R2R processing system 400 of FIG. 4.
• the current-collector web 324 may be provided in another form, such as in sheet form whereby the current collector material is provided as individual sheets.
• the current-collector web 324 may be made of any suitable electrically conductive materials, such as a metal, for example, copper, nickel, titanium, or stainless steel, among others, or any suitable metal alloy. Fundamentally, there is no limitation on the type of material used for the current-collector web.
• the current-collector web 324 may have any of a variety of forms, such as solid foil, perforated foil, woven mesh, or expanded mesh, among others. Fundamentally, there is no limitation on the form of the current-collector web 324. Any mesh or other open structure may have a percentage of open area to total area in a range of about 5% to about 95%. Perforated mesh, if used, can be made by any of various processes, including, but not limited to, traditional perforating, rotary die-cutting, electroforming, photo-etching, and laser cutting, among others.
• the current-collector web 324 has a width, Ww, in a range of about 20 mm to about 200 mm, in a range of about 120 mm to about 200 mm, in a range of about 150 mm to about 300 mm, or larger, especially when the thickness of the anode-active material Tam is about 50 pm or less and the active material is an alkali metal, such as lithium.
• the length of the current-collector web 324 may be any suitable length to accommodate implementing an anode-forming lamination method of the present disclosure, such as anode-forming lamination method 200 of FIG. 2 in a ribbon-based process or a sheet-based process.
• the tabs 308B of the current collectors 308 of the anodes 300 may be formed from bare regions 304A of the current-collector web 324, i.e., regions of the current-collector web that do not have any anode-active material present, and, if the optional conductive coating 316 is used, also do not have any conductive coating material present. Consequently, this requires that the tab portions 320B(l) to 320B(3) of the anode regions 320 of the webbed anode precursor 304 be bare, as discussed below.
• an optional conductive-coating patch 328 is applied to one or each side of the current-collector web 324 depending, for example, on whether or not the finished anode 300 will have anode-active material on one or both sides of the current-collector web.
• FIG. 3A only a single conductive-coating patch 328 is shown, but in this example a similar conductive- coating patch is also on the opposite side of the current-collector web 324.
• the conductive coating is provided in conductive-coating patches 328 to provide inter-patch regions 304 A that are bare portions of the current-collector web 324 wherein the tab portions 320B of the anode regions 320 are/will be located and from which the tabs 308B of the anode 300 are/will be formed.
• Each inter-patch region 304 A can have a gap width, Wg, equal to or greater than the length, Lt, of the corresponding tab 308B on the respective anode 300.
• the gap width Wg may be in a range of about 10 mm to about 30 mm based on the length Lt of the tabs 308B being of the same or similar dimension.
• the gap width Wg of each inter-patch region 304 A may be greater than about 30 mm or less than about 10 mm to suit a particular anode design.
• each conductive-coating patch 328 is about equal to the width Wa of the active-material region 308 A of the anode 300 to minimize waste.
• the width Weep of each conductive-coating patch 328 is greater than the width Wa of the active- material region 308A by about 1 mm to about 3 mm, or more, on each side of the active-material region 308 A to ensure that when the anodes 300 are removed from the webbed anode precursor 304, conductive material is present at the cut edges of the anodes.
• the width, Weep, of each conductive-coating patch 328 is about equal to the width Ww of the current-collector web 324, especially when the method 200 is used to create the anodes 300 from a single line of anode regions 320.
• the width Weep of each conductive-coating patch 328 is made to be less than about 95% of the width of the current-collector web 324 so as to leave enough of the current-collector web intact for easy handling of the waste material. For example, with enough of the current-collector web 324 remaining after removing the anodes 300 in an R2R system, such as R2R system 400 of FIG.
• the waste material can be rolled onto a waste-collection roll (not shown).
• the width Weep of each conductive-coating patch 328 and/or width Waamp corresponding anode-active-material patch 336 is made to be less than 100% of the width Ww of the current-collector web 324, such as, for example, about 0.9Ww ⁇ Weep and/or Waamp ⁇ Ww, about 0.95Ww ⁇ Weep and/or Waamp ⁇ Ww, or about 0.98Ww ⁇ Weep and/or Waamp ⁇ Ww, among others.
• the length, Lccp, of each current-collector patch 328 is made to be about equal to the length La of the activematerial region 308A of the anode 300 to minimize waste. In some embodiments, the length Lccp of each conductive-coating patch 328 is greater than the length La of the active-material region 308A by about 1 mm to about 3 mm on each side of the active-material region 308 A to ensure that when the anodes 300 are removed from the webbed anode precursor 304, having conductive material present at the cut edges of the anodes is ensured.
• the conductive coating should typically be either flush with or extend at most about 1 mm beyond the anode-active-material patch 336.
• the conductive-coating patch 328 and the anode-active-material patch 336 not extend more than about 1.5 mm onto the tab 308B. Otherwise that “excess” material may interfere with the tab welding process.
• Each conductive-coating patch 328 may act as a primer relative to the corresponding anode-active-material patch 336 to help improve adhesion therebetween while maintaining low contact resistance between the anode-active-material 312 and the current-collector 308 in the final anode 300.
• each conductive-coating patch 328 may be made of any suitable conductive material, such as a conductive-carbon material that includes one or more types of conductive-carbon particles and a suitable binder to bind the particles with one another and to the current-collector web 324.
• conductive-carbon particles can be augmented with metal particles, while in still other embodiments, only metal particles may be used along with a suitable binder.
• a conductive-carbon material it may be provided as a slurry prepared by blending conductive carbon and a binder material in an aqueous or organic solvent medium that is eventually dried after being applied to the current-collector web 324.
• conductive carbon material examples include carbon black, graphite, graphene, carbon fibers, carbon nano tubes, or a mixture thereof.
• Metals, such as silver, in a powder form can also be mixed in with the conductive carbon to enhance electrical conductivity.
• binder material examples include, but are not limited to PVDF (polyvinylidene fluoride), PVDF-HFP (polyvinylidene fluoride - hexafluoropropylene), CMC (carboxymethyl cellulose) and SBR (styrene-butadiene rubber), PAA (poly(acrylic acid)), and any mixture thereof.
• PVDF polyvinylidene fluoride
• PVDF-HFP polyvinylidene fluoride - hexafluoropropylene
• CMC carbboxymethyl cellulose
• SBR styrene-butadiene rubber
• PAA poly(acrylic acid)
• the binder in the conductive-coating patches 328 can help the anode- active-material patches 336 adhere well to the current-collector web 324 and prevents delamination of anode-active material from the current-collector web and current collector 308 during handling and use.
• the conductive material(s) in the conductive-coating helps to maintain a low contact resistance between the anode-active material 312 and the current collector 308 in the finished anode 300, which together with better adhesion helps to improve cell-cycle performance in secondary batteries made using anodes incorporating such conductive material(s).
• each conductive-coating patch 328 may be, for example, in a range of about 0.1 um to about 5 um, in a range of about 0.5 pm to about 2 pm, and about 1 pm, among other ranges and values.
• the thickness of the coating may be in a range of about 0.2X pm to about 2X pm.
• Current evidence demonstrates that in some embodiments (including embodiments in which lithium foil is used for the anode-active-material patches 336, a thickness of about 1 pm for each conductive-coating patch 328 can be optimal based on the following considerations.
• the conductive-coating patches 328 need to be substantial enough to improve adhesion and conductivity. However, thicker coatings can generate side reactions and add unnecessary weight and volume to a cell. In addition, it may be that there is a minimum thickness that accommodates variation in average surface roughness of the anode-active material (e.g., lithium). The relationship may be directly or inversely proportional depending on a number of factors. For example, in the context of lithium, lithium metal easily deforms, and a lithium foil with higher roughness might easily latch on to, for example, a copper surface, and a thin conductive- coating may be all that is needed.
• the anode-active material e.g., lithium
• the areal loading of the conductive-coating material in each conductive-coating patch 328 may be in a range of about 0.1 g/m 2 to about 2 g/m 2 and in some embodiments about 0.5 g/m 2 .
• the surface resistance of each conductive- coating patch 328 may be below about 30 ohms/sq for a coating thickness of about 1 pm, and the surface resistivity may be below about 3x10' 3 ohm-cm.
• the units of surface resistance is ohms/sq, and the surface resistance depends on the thickness of the each conductive-coating patch 328, with the thicker the conductive-coating patch, the lower the resistance.
• the surface resistance will be different from 30 ohms/sq.
• the amount of conductive material (e.g., conductive carbon, conductive metal, or combination thereof) in the conductive- coating material may be in a range of about 5 wt.% to about 95 wt.%, in a range of about 50 wt.% to about 90 wt.%, in a range of about 60 wt.% to about 90 wt.%, or in a range of about 70 wt.% to about 90 wt.%.
• the conductive-coating patches 328 in the context of the anode-active material being lithium and the current-collector web 324 being copper, fresh lithium typically adheres well to copper surface.
• the passivation layer that is typically present on the surface of conventional lithium foils inhibits its adhesion to copper.
• the composition of the passivation layer depends on the atmosphere to which the lithium foil was exposed to initially during manufacture and is typically made of salts such as lithium carbonate, lithium hydroxide, lithium oxide, and lithium nitride.
• the surface of lithium foil may also have residual lubricants from the roll-milling process used to form the lithium foil.
• Providing the conductive- coating patches 328 helps overcome this issue by providing a layer that adheres well to the current-collector web 324 and to which the anode-active-material patches 336 adheres well.
• a peel test was applied to samples of lithium foil (anode-active material) pressure-laminated to a copper foil (current collector) — one with the lithium foil applied directly to the copper foil and one with a conductive-carbon coating present between the lithium foil and the copper foil.
• a piece of SCOTCH® tape (available from 3M Corporation, St. Paul, Minnesota) was gently pressed onto the lithium foil of each sample and then peeled slowly.
• the lithium foil that was laminated directly to the copper foil peeled off of the copper foil along with the tape whereas the lithium foil laminated to the conductive- carbon coating did not peel off with the tape and remained laminated to the conductive-carbon coating and the copper foil beneath the conductive-carbon coating.
• a pressuresensitive tape other than SCOTCH® tape can be used. If the lithium foil is adhered well to the copper foil, then the peel force would typically be greater than about 200 N/m.
• example R2R system 400 may include coating-application equipment 408 suitable for the type of conductive-coating material at issue.
• coating-application equipment 408 may include one or more coating applicators 408A(l) and 408A(2) that may be knife-type applicators, spray applicators, or roller applicators, among others.
• Example coating processes that can be used include slot-die casting, tape casting, gravure, comma, spray coating, and dip coating, among others. Fundamentally, there are no limitations on the manner in which the conductive-coating patches 328 may be applied.
• Coating-application equipment 408 may also include one or more patterning devices 408B(l) and 408B(2), such as an open mask or silk screen, among others, for ensuring that the conductive- coating patches are of the desired size.
• patterning devices 408B(l) and 408B(2) such as an open mask or silk screen, among others, for ensuring that the conductive- coating patches are of the desired size.
• a metal foil 332 is laminated on one or each side of the current-collector web 324 as a corresponding anode-active-material patch 336 (only one shown, but in this example another anode-active-material patch is present on the opposite side of the current-collector web).
• the lamination of the metal foil 332 may first include engaging the metal foil 332 with the currentcollector web 324, with or without the conductive- coating patches 328 depending on whether or not they are used in a particular application.
• the engaging of the metal foil 332 can be performed in any suitable manner, such as, for example, via transfer from a temporary holding substrate or via a pick and place system, among others.
• the metal foil 332 may be pressed into firm engagement with the current-collector web 324 or, if present, to each corresponding conductive- coating patch 328. Such pressing may be performed in any suitable manner, such as, for example, using a roller press or stationary press, among others.
• lamination of the metal foil 332 may be performed using a roll-mill or calendaring machine, wherein the lamination pressure is determined by the gap setting between the rolls. In some embodiments, the pressure applied by the rollers should not deform the metal foil 332 significantly, i.e., there should be a negligible reduction in thickness or increase in width and/or length of lithium foil.
• the metal foil 332 in the corresponding anode-active-material patch 336 remain about within the footprint of the underlying conductive-coating patch.
• the metal foil 332 may have a thickness in a range of about 15 pm to about 25 pm in some embodiments, of about 20 pm in some embodiments, in a range of about 10 pm to about 50 pm in some embodiments, and in a range of about 1 pm to about 100 pm in some embodiments, among other ranges and values. These thicknesses are particularly applicable to lithium-containing, including pure lithium, alkali-metal-based foils generally, and foils based on one or more other metals.
• the thickness of the currentcollector web 324 may be in a range of about 4 pm to 10 pm and in some embodiments about 6 pm, including the case wherein the current-collector web is a copper foil, among other ranges and values.
• 6 pm for the current-collector thickness can be an optimal tradeoff of, for example, weight, strength, energy density, complexity of lamination, cost, and thickness, among other things.
• the metal foil 332 may be pre-sized to be about equal to the size of the active region portions 320A(l) to 320A(3) of the anode regions 320(1) to 320(3) or to the size of the corresponding conductive-coating patch 328, or both. Such sizing could be used, for example, in a transfer process from a temporary substrate or in a pick-and-place process, such as a pick-and- place process using a suitably gentle vacuum.
• the metal foil 332 may be provided in a continuous sheet or ribbon.
• the anode-active-material patches 336 may be formed by pressing the continuous sheet or ribbon to the current-collector web and removing the portions of the metal foil 332 from the previously bare portions of the current-collector web where the metal foil does not adhere well.
• the width, Waamp, of each anode-active-material patch 336 is about equal to the width Wa of the active-material region 308 A of the anode 300 to minimize waste.
• the width Waamp, of each anode-active-material patch 336 is greater than the width Wa of the active-material region 308A by about 1 mm to about 3 mm on each side of the active-material region 308A to ensure that when the anodes 300 are removed from the webbed anode precursor 304, conductive material is present at the cut edges of the anodes.
• the method 200 may include, at an optional sub-block 215A, using the conductive-coating patches to align sheets of the metal foil 332 with the conductive-coating patches.
• a suitable detection system can be provided to sense the contrast and provide location information to a control system that controls the registration of the sheets of the metal foil 332 with the conductive- coating patches.
• An example of a detection system is a machine-vision system that can detect and locate one or more edges of each conductive-coating patch 328.
• the R2R system may include a lamination region 412 where the metal foil 332 (only some labeled in FIG. 4) is engaged with and laminated to the current-collector web 324.
• the lamination region 412 may take any of a wide variety of forms, depending on, for example, the manner in which the metal foil 332 is delivered to the current-collector web 324, whether or not conductive-coating patches 328 are used, and the manner in which the metal foil is pressed onto the current-collector web.
• the metal foil 332 is delivered as individual foil sheets 416 (only some labeled in FIG.
• the embodiment shown also includes a roller press 424 that presses the foil sheets 416 into firm engagement with the current-collector- web ribbon 404 to form the anode-active-material patches 336.
• the foil sheets 416 are delivered to the current-collector- web ribbon 404 using a pair of transfer rollers 428(1) and 428(2) that may, for example, apply a relatively small amount of pressure to effect the transfer of the foil sheets to the current-collector-web ribbon. Due to a greater adhesion between the foil sheets 416 with the current-collector- web ribbon 404, especially when the conductive-coating patches 328 are present, than between the foil sheets and the temporary support ribbon 420(1) and 420(2), the temporary support ribbons can be easily peeled away from the anode-active-material patches 336 now part of the webbed anode precursor 304.
• the spacing between the foil sheets 416 on the temporary support ribbons 420(1) and 420(2) precisely matches the inter-patch regions 304 A. In other embodiments, the spacing between the foil sheets 416 on the temporary support ribbons 420(1) and 420(2) may not match the inter-patch regions 304A. In some embodiments when the spacing between the foil sheets 416 on the temporary support ribbons 420(1) and 420(2) precisely matches the inter-patch regions 304A, all of the temporary support ribbons 420(1) and 420(2) and the current-collector-web ribbon 404 may be run through the roller press 424. In that case, the transfer rollers 428(1) and 428(2) may be eliminated.
• example R2R system 400 may optionally include an alignment system 432 that utilizes the conductive- coating patches to precisely align the foil sheets 416 with corresponding respective ones of the conductive- coating patches. This alignment puts each foil sheet 416 into proper precise registration with a corresponding one of the conductive coating patches 328 prior to that anode-active-material sheet being firmly laminated by the roller press 424 to create the corresponding anode-active-material patch 336.
• the alignment system 432 may include one or more optical sensors, here two optical sensors 432A(1) and 432A(2), for detecting and locating at least one edge of each conductive-coating patch.
• the alignment system 432 may also include one or more controllers 432B (only one shown) and one or more actuators, such as stepper motors (not shown), that the controller controls to precisely advance each of the temporary support ribbons 420(1) and 420(2).
• the controller 432B may be programmed to use location information for the one or more edges from the optical sensors 432A(1) and 432A(2) and position information for the temporary support ribbons 420(1) and 420(2) to precisely control the registrations of the foil sheets 416 with the corresponding ones of the conductive-coating patches 324.
• location information for the one or more edges from the optical sensors 432A(1) and 432A(2) and position information for the temporary support ribbons 420(1) and 420(2) to precisely control the registrations of the foil sheets 416 with the corresponding ones of the conductive-coating patches 324.
• Example method 200 further includes a block 220 at which the anodes 300 are formed from the webbed anode precursor 304.
• the anodes may be formed from the webbed anode precursor 304 in any suitable manner, such as by punching, sheering, or otherwise cutting the webbed anode precursor 304 at the anode regions, for example, the anode regions 320(1) to 320(3) to define and liberate the resulting anodes 300 therefrom.
• FIG. 4 illustrates example R2R system 400 as including anode-forming equipment 436, which may include any suitable automated punching, sheering, or other cutting tool(s), that may be configured to form one or more of the anodes 300 at a time.
• the formed anodes 300 may now be ready for use in the next step of making one or more electrochemical devices (not shown) using the anodes 300 so formed.
• FIGS. 5A to 5E illustrate some example alternative arrangements of anode regions and anode-active-material patches (and underlying conductive-coating patches, if any) on various webbed anode precursors that can be used in place of the arrangements of anode regions 320 and anode-active-material patches 336 (and if present, conductive-coating patches 328) on webbed anode precursor 304 of FIG. 3 A. It is noted that alternatives to the arrangements illustrated relative to webbed anode precursor 304 of FIG. 3 A are not limited to the alternative arrangements of FIGS. 5 A to 5E; rather these are example arrangements provided to illustrate the flexibility of methods of forming anodes in accordance with the present disclosure. In describing FIGS.
• FIGS. 5 A to 5E below, no references are made to conductive-coating patches to simplify the explanation. However, as just noted, conductive-coating patches may indeed be present beneath the corresponding anode-active- material patches, for example, in a manner discussed above in connection with FIGS. 2 to 4. It is also noted that the alternative arrangements of FIGS. 5 A to 5E are described as if the anode-active- material patches are located on only the obverse side of the webbed anode precursors as seen in the figures.
• the reverse side of the webbed anode precursors may likewise have matching anode-active-material patches (and optionally conductive-coating patches) in registration with the anode-active-material patches on the obverse side of the webbed anode precursors.
• the anode regions in FIGS. 5 A to 5E may be the same as or similar to anode regions described elsewhere in this disclosure, such as relative to anode regions 320(1) to 320(3) of FIG. 3A.
• FIG. 5 A illustrates an example webbed anode precursor 500 in which the anode-active- material patches 504(1) to 504(5) (solid lines) are provided in a single line on the underlying currentcollector web 508.
• each anode-active-material patch 504(1) to 504(5) is provided for forming a single anode region 512(1) to 512(5) (dashed lines) that will eventually be removed from the webbed anode precursor 500 to form a corresponding anode (not shown, but similar to anode 300 of FIGS. 3 A and 3B).
• a difference between webbed anode precursor 500 of FIG. 5A and webbed anode precursor 304 of FIG. 3A is that the tab portions 512A, here 512A(2) to 512A(5), of immediately adjacent pairs of the anode regions 512(2) to 512(5) are located in the same inter-patch regions 516, here 516(1) and 516(2).
• This arrangement can provide less waste of the current collector web 508, as the inter-patch regions 520, here 520(1) and 520(2), can be made smaller than the inter-patch regions 516 that contain the pairs of tab portions 512A(2) to 512A(5).
• FIG. 5B is generally similar to FIG. 5A, except that the feature of minimizing the size of the inter-patch regions 520 (FIG. 5A) is taken to the extreme in FIG. 5B by eliminating those interpatch regions altogether.
• each pair of anode-active-material patches 504(1) to 504(4) on opposite sides of the interpatch regions 520 (FIG. 5 A) are, in FIG. 5B, effectively joined together into a single anode-active-material patch 524, here 524(1) and 524(2) that, in this example, is about twice the size of each of the anode-active-material patches 504(1) to 504(5) of FIG. 5 A.
• FIG. 5B is provided for forming two anode regions 528, here the anode regions 528(1) and 528(2) at the anode-active-material patch 524(1) and the anode regions 528(3) and 528(4) at the anode-active-material patch 524(2).
• the configuration of FIG. 5B may not be achievable.
• the anode-active material is lithium
• processing limitations may limit the length of the anode-active-material patches, such as the anode-active-material patches 504 and 524 of FIG. 5 A and 5B, respectively, that can be made.
• FIGS. 5C to 5E respectively, illustrate multiline variants 530, 550, and 570 of the example configurations shown in FIGS. 3A, 5A, and 5B.
• the reader can reference FIGS. 3 A, 5 A, and 5B and the corresponding description for information on the corresponding single-line configuration, as each of these multiline variant can be made by starting with a larger (e.g., wider) current-collector web, here 534, 554, and 574, respectively, and repeating the corresponding single-line configuration multiple times on such larger current-collector web.
• a larger current-collector web here 534, 554, and 574
• each of the variants 530, 550, and 570 of FIGS. 5C to 5E shows two lines 538(1) and 538(2), 558(1) and 558(2), and 578(1) and 578(2) of anode-active-material patches 542 (here, 542(1) to 542(6)), 562 (here, 562(1) to 562(10)), and 582 (here, 582(1) and 582(4)), in other embodiments, a greater number of lines can be provided.
• the only limitations on the number of lines 538, 558, and 578 implemented are the availability of sufficiently large current-collector webs 534, 554, and 574 and the ability to make the corresponding fabrication equipment.
• each of the current-collector webs 534, 554, and 574 may be, for example, of a sheet type or a ribbon type depending on the type of processing equipment used.
• ribbon-type currentcollector webs are readily amenable to R2R processing, such as in an R2R system similar to the R2R system 400 of FIG. 4.
• FIGS. 3 A through 5E show all of the anode regions, and correspondingly the anode-active-material patches, any conductive-coating patches, if any, and anodes formed therefrom, as being uniform in size in each figure.
• this would be typical for a production run for electrochemical cells of a common size this need not be so.
• some embodiments of anode-forming methods of the present disclosure may be adjusted to make anodes of differing sizes on the same webbed anode precursor.
• FIG. 6 is a graph of discharge capacity versus cycle number comparing the cell cycle life performance of lithium-copper (Li/Cu) anodes (20-pm-thick Li, double-side on Cu, 8-pm-thick Cu, 1-pm-thick coating made of between about 70% to about 90% carbon black and PVDF) with and without using a conductive coating of the present disclosure.
• cycle-life test was performed in multi-layer pouch cells built with nickel-manganese-cobalt (NMC) oxide-based cathodes and microporous polyolefin-based separators. The pores in the cathode and separator are filled with a Li + conducting liquid electrolyte.
• the electrolyte typically contains a lithium salt such as LiPFe or LiFSI dissolved in a carbonate or ether-based solvent.
• the cells were cycled between 2.5V to 4.3V at a C/5-1C charge-discharge rate.
• FIG. 6 including a conductive coating of the present disclosure on the copper current collector has been found to enhance the cycle-life performance of cells with lithium anode.
• the dense lithium gradually became a more porous structure, and the conductive coating helped to maintain a good electrical contact between the porous lithium and the copper current collector substrate. This further lead to more uniform current density distribution and uniform lithium plating/stripping and, consequently, to an enhanced cycle life performance.
• ASI area specific impedance
• an electrically conductive coating of the present disclosure such as the optional conductive coating 316 of example anode 300 of FIGS. 3 A
• the anode need not be made using a lamination method of the present disclosure.
• the anode-active material which is equivalent to the anode-active material 312 of anode 300, may be applied using another method, such as vapor deposition, among other potential techniques that are or may be under development.
• FIG. 7 illustrates an example secondary battery 700 made in accordance with the present disclosure.
• the example battery 700 includes a stacked jellyroll 704 that includes a plurality of anodes 708 that either include an electrically conductive coating (not shown) of the present disclosure, such as the conductive coating 316 of FIG. 3 A, or are made using a lamination method of the present disclosure, such as the lamination method 200 of FIG. 2, or both.
• Novelty of the example secondary battery 700 can arise from the novelty of the anodes 708 themselves in terms of presence of a unique conductive-coating layer (not shown, but see, e.g., conductive coating 316 of FIGS.
• the stacked jellyroll 704 also includes a plurality of separator layers 716 and a plurality of cathodes 720 electrically separated from the anodes 708 by the separator layers.
• the stacked jellyroll 704 is sealed within a casing, here, a pouch-type casing 712, along with a suitable electrolyte (not illustrated, but present in at least the separator layers 716 (not all labeled), which may be considered part of a polymer electrolyte if a solid- or geltype electrolyte is used).
• the pouch-type casing 712 may be replaced with a casing of a differing type, such as a rigid-wall housing, among others.
• the type of casing is important only to the extent that it provides the requisite functionalities, including providing a sealed volume for containing the stacked jellyroll 704 and the electrolyte.
• each anode 708 may include any suitable anode-active metal, such as lithium, sodium, potassium, magnesium, or aluminum, or any suitable combination thereof, just as with example anode 300 discussed above.
• each cathode includes a suitable cathode-active material.
• the cathode has a general formula of Li x M y O z , where M is a transition metal such as Co, Mn, Ni, V, Fe, or Cr.
• each cathode 720 may comprise a layered or spinel oxide material selected from the group comprising of LiCoCh, Li(Nii/3Mm/3Coi/3)O2, Li(Nio.sCoo.i5Alo.o5)02, LiM C , Li(Mm.5 ⁇ 0.5)264, or their lithium rich versions.
• each cathode 720 may have a general formula of Li x M y PO z , wherein M is a transition metal such as Co, Mn, Ni, V, Fe, or Cr.
• each cathode 720 may be a phosphate material selected from the group comprising of LiFePO-i, LiNiPO-i, LiCoPO-i, or LiMnPO-i.
• each cathode 720 may comprise a porous coating comprising a cathode-active material powder, a polymeric binder, such as PVDF, and a conductive diluent such as carbon black.
• each cathode 720 may comprise a porous coating on aluminum foil.
• each cathode 720 may include lithium cobalt oxide (or lithium cobaltate), lithium manganese oxide (also known as spinel or lithium manganate), lithium iron phosphate, as well as lithium nickel manganese cobalt (or NMC) and/or lithium nickel cobalt aluminum oxide (or NCA).
• lithium cobalt oxide or lithium cobaltate
• lithium manganese oxide also known as spinel or lithium manganate
• lithium iron phosphate lithium iron phosphate
• NMC lithium nickel manganese cobalt
• NCA lithium nickel cobalt aluminum oxide
• each cathode 720 may comprise a nanosized and nanostructured sulfur-based composite, such as a sulfur-impregnated core-shell hierarchical porous carbon (HPC) composite, a sulfur/graphene nanosheet (GNS) composite, a sulfur@rGO (reduced graphene oxide) composite with a saccule-like structure, and a C-S@PANi (polyaniline) composite with polymer spherical network structured, among others.
• each cathode 720 may comprise carbon layers sandwiched around a current collector and then covered with a polymer film, such as a PTFE film.
• the carbon layers may contain a metal catalyst that enhance the oxygen reduction kinetics and increase the specific capacity of the cathode 720.
• Example metal catalysts include, but are not limited to, manganese, cobalt, ruthenium, platinum, silver, and mixtures thereof.
• each separator layer 716 when the electrolyte is a liquid, each separator layer 716 may be made of any one or more materials, at least one of which is a dielectric.
• each separator layer 716 may be made of polypropylene or polyethylene or any suitable combination (e.g., mixture, layers, coating, etc.) thereof.
• suitable combination e.g., mixture, layers, coating, etc.
• the secondary battery 700 is a lithium-metal battery, meaning that the anodes 708 comprise lithium metal to/from which lithium ions are deposited and stripped during, respectively, charging and discharging cycles.
• the electrolyte contains lithium ions (not shown) that flow between the anodes and cathodes 720 within the stacked jellyroll 704 during the charging and discharging cycles. Consequently, in this example the electrolyte includes one or more lithium-based salts in a suitable form, such as in a solution, a eutectic mixture, or a molten form, among others.
• the electrolyte may contain one or more solvents, one or more performance and/or property enhancing additives, and/or one or more polymers, among other things.
• the electrolyte may be in any suitable state of matter, such as liquid, gel, or solid state.
• the composition of the electrolyte, whether it is for a lithium- metal-based version of the secondary battery 700 or a version based on another type of metal (e.g., sodium, potassium, aluminum, magnesium, among others), can be any composition suitable for the particular application at issue and can be determined by the designer of the particular instantiations of the secondary battery.
• Example salts that can be used in the electrolyte include, but are not limited to, LiFSI, LiTFSI, and lithium fluorosulfonyl(trifhioromethylsulfonyl)imide (LiFTFSI), LiPFe, LiAsFe, LiBF4, LiBOB, and Li-triflate, and any combination thereof, among others.
• LiFSI lithium fluorosulfonyl(trifhioromethylsulfonyl)imide
• LiPFe LiAsFe
• LiBF4 LiBOB
• Li-triflate Li-triflate
• two or more salts can be combined in a eutectic mixture, such as a eutectic mixture that includes a first salt, Xi + Yf, and a second salt, X2 + Y2‘, wherein each of XI + and Xi + is an alkali metal cation and Xl + is different from Xi + , and each of Yf and Y2‘ is a sulfonimide anion and Yf is different from Y2’.
• a eutectic mixture such as a eutectic mixture that includes a first salt, Xi + Yf, and a second salt, X2 + Y2‘, wherein each of XI + and Xi + is an alkali metal cation and Xl + is different from Xi + , and each of Yf and Y2‘ is a sulfonimide anion and Yf is different from Y2’.
• Yf and Y2‘ may be selected from the group consisting of FSO2N SO2F (FSF) and FSO2N SO2CF3 (FTFSF) and/or Xi + and Xi + may be selected from the group consisting of Li + , Na + , K + , Rb + , and Cs + .
• the eutectic mixture may further include a third salt, XEYf, wherein XE is different from each of Xi + and Xi + .
• Yf, Yi', and Ys’ may be selected from the group consisting of FSO2N SO2F (FSF) and FSO2N SO2CF3 (FTFSF) and/or Xi + , Xi + , and Xs + may be selected from the group consisting of Li + , Na + , K + , Rb + , and Cs + .
• the electrolyte may include an imide salt, for example, lithium bisfluorosulfonylimide (LiN(FSO2)2 , and a perchlorate salt in an aprotic solvent.
• an imide salt for example, lithium bisfluorosulfonylimide (LiN(FSO2)2
• a perchlorate salt in an aprotic solvent.
• Other lithium imide salts with a fluorosulfonyl (FSO2) group e.g., LiN(FSO2)2, LiN(FSO2)(CF3SO2), LiN(FSO2)(C2F5SO2), can be used instead of or in any combination with lithium bisfluorosulfonylimide (LiN(FSO2)2.
• the perchlorate salt may include LiClO4.
• the perchlorate salt has a concentration between 0.05M moles/liter to 0.50M moles/liter of the organic solvent. In one or more embodiments, the perchlorate salt is selected from the group consisting of LiCICU, Ca(C104)2, Sr(C104)2, Mg(C104)2, Ba(C104)2, and any combination or mixture thereof.
• such electrolyte may further include a diluent selected from the group consisting of a fluorinated glyme and a fluorinated ether.
• the fluorinated diluent can allow the use of more-stable longer-sidechain glyme-based solvents (such as DEE (1,2-diethoxyethane or ethylene glycol diethyl ether), DPE (1,2-dipropoxy ethane or ethylene glycol dipropyl ether), DBE (1,2-dibutoxyethane or ethylene glycol dibutyl ether), diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, triethylene glycol diethyl ether, triethylene glycol dipropyl ether, triethylene glycol dibutyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dipropyl ether, tetraethylene glycol dibutyl, etc.
• DEE 1,2-diethoxyethane or ethylene glycol diethyl ether
• DPE 1,2-dipropoxy ethane or ethylene
• the diluent may be the fluorinated ether l,l,2,2-tetrafluoroethyl-2,2,3,3- tetrafluoropropyl ether (TTE), or the fluorinated ether bis(2,2,2-trifluoroethyl) ether (BTFE).
• TTE fluorinated ether l,l,2,2-tetrafluoroethyl-2,2,3,3- tetrafluoropropyl ether
• BTFE fluorinated ether bis(2,2,2-trifluoroethyl) ether
• the diluent of may include suitable hydrocarbon molecules having at least one oxygen (-O-) linkage and at least one fluorine (-F) substitution.
• DEE and TFE are combined with one another.
• the solvent: diluent ratio of an electrolyte made in accordance with this paragraph may by in a range of about 10:90 to 100:0. In one or more embodiments, the solvent: diluent ratio may be desired to be in a range of about 40:60 to about 90: 10, and in one or more embodiments the solvent: diluent ratio may be desired to be in a range of about 60:40 to about 80:20.
• the electrolyte may be a free-solvent-free liquid lithium sulfonimide salt composition consisting essentially of an adduct of molecules of a lithium sulfonimide salt and molecules of at least one anhydrous ether-based solvent.
• examples of lithium sulfonimide salt compositions that can be used for the anhydrous lithium sulfonimide salt include, but are not necessarily limited to, LiFSI, LiTFSI, and (LiFTFSI), and examples of anhydrous ether-based solvents that can be used for the one or more anhydrous ether-based solvents include, but are not necessarily limited to, dimethoxy ethane, ethoxymethoxyethane, diethoxyethane, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, dioxane, and crown ethers, among others. Generally, any ether-based solvent can be used.
• substantially all molecules of the at least one ether- based solvent are coordinated with molecules of the at least one lithium sulfonimide salt.
• the at least one ether-based solvent is present in the free-solvent-free lithium sulfonimide salt composition in an amount less than 5% by weight of the free-solvent-free lithium sulfonimide salt composition.
• the electrolyte contains a cyclic carbonate, such as ethylene carbonate or propylene carbonate, and their derivatives, as an organic solvent.
• the electrolyte contains a linear carbonate, such as dimethyl carbonate, diethyl carbonate or ethyl methyl carbonate. In one or more embodiments, the electrolyte contains a cyclic ether, such as tetrahydrofuran or tetrahydropyran, and their derivatives, as an organic solvent. In one or more embodiments, the electrolyte contains a glyme, such as dimethoxyethane, diethoxyethane, triglyme, or tetraglyme, and their derivatives, as an organic solvent.
• the electrolyte contains an ether such as diethylether, or methybutylether and their derivatives, as an organic solvent.
• the electrolyte contains a sulfonyl solvent such as N,N-dialkyl sulfamoyl fluoride and their derivatives and combinations thereof, as an organic solvent.
• the electrolyte contain a mixture of organic solvents of the same type or a mixture of organic solvents of two or more types.
• the electrolyte may comprise one or more inorganic electrolytes selected from the group consisting of lithium silicates, lithium borates, lithium aluminates, lithium phosphates, lithium oxynitrides, lithium oxyborides, lithium silicosulfides, lithium borosulfides, lithium aluminosulfides, lithium phosphosulfides, and any combination thereof.
• the electrolyte may comprise one or more solid ceramic electrolytes such as the Al-doped LLZO (Li6. 2 5Alo. 2 5La3Zr 2 Oi 2 ) garnet oxide, perovskite (Lio.
• LISICON Lii 4 ZnGe 4 0i6
• NASICION Lii.3Alo.3Tii. 7 (P0 4 )3
• thio-LISICON LiioGeP 2 Si 2
• other glass LiPON
• glass-ceramic 70Li 2 S -30P 2 S5
• the electrolyte may comprise a solid or gel based polymer electrolyte having PEO (poly ethylene oxide), PPO (poly propylene oxide), PAN (poly acrylonitrile), PMMA (poly methyl methacrylate), PVC (polyvinyl chloride), PVDF (poly vinylidene fluoride), PVDF-HFP (poly vinylidene fluoride - hexafluoropropylene), (poly(acrylic acid)), or any mixture thereof.
• PEO poly ethylene oxide
• PPO poly propylene oxide
• PAN poly acrylonitrile
• PMMA poly methyl methacrylate
• PVC polyvinyl chloride
• PVDF poly vinylidene fluoride
• PVDF-HFP poly vinylidene fluoride - hexafluoropropylene
• poly(acrylic acid) poly(acrylic acid)
• an electrolyte of the present disclosure may have a salt concentration in a range of about 0. IM to about 10M, while in some embodiments the salt concentration may be desired in a range of about IM to about 5M, and in other embodiments the salt concentration may be desired in a range of about 2M to about 3M.
• the example secondary battery 700 also includes a positive terminal 724 electrically connected to each of the cathodes 720 via corresponding electrodes 728(1) to 728(5).
• the lithium-metal battery further includes a negative terminal 732 electrically connected to the tabs 708A of the anodes 708 via corresponding electrodes 736(1) to 736(4).
• the present disclosure is directed to an anode for an electrochemical device.
• the anode includes a current collector having a thickness and an active region, wherein the active region has first and second sides on opposite sides of the thickness; a first metal foil secured to the current collector on the first side of the active region; and a first electrically conductive layer between the current collector and the first metal foil, wherein the first electrically conductive layer secures the first metal foil to the current collector.
• the first electrically conductive layer comprises an electrically-conductive-carbon layer.
• the electrically-conductive-carbon layer consists essentially of electrically-conductive-carbon particles and a binder.
• the electrically-conductive-carbon particles are present in an amount of about 50 wt.% to about 90 wt.%, of about 60 wt.% to about 90 wt.%, or about 70 wt.% to about 90 wt.% of the electrically-conductive-carbon layer.
• the electrically conductive layer has a thickness in a range of about 0.1 pm to about 5 pm. [0066] In one or more embodiments of the anode, the electrically conductive layer has a thickness in a range of about 0.5 pm to about 2 pm.
• the electrically conductive layer has a thickness of about 1 pm.
• the electrically conductive layer is present in an areal loading of about 0.1 g/m2 to about 2 g/m2.
• the current collector comprises copper
• the first metal foil comprises lithium
• the current collector has a thickness in a range of about 4 pm to about 10 pm
• the first metal foil has a thickness in a range of about 15 pm to about 25 pm.
• the anode includes a second metal foil secured to the current collector on the second side of the active region; and a second electrically conductive layer between the current collector and the second metal foil, wherein the second electrically conductive layer secures the second metal foil to the current collector.
• the present disclosure is directed to an electrochemical device comprising a cathode, an electrolyte, and an anode of any one of the anodes recited herein.

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• 2023
  • 2023-01-25 JP JP2024544426A patent/JP2025503963A/ja active Pending
  • 2023-01-25 KR KR1020247024007A patent/KR20240139052A/ko active Pending
  • 2023-01-25 CN CN202380016928.6A patent/CN118541818A/zh active Pending
  • 2023-01-25 EP EP23703322.0A patent/EP4470047A1/de not_active Withdrawn
  • 2023-01-25 WO PCT/IB2023/050642 patent/WO2023144729A1/en not_active Ceased

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